Energy flow in food webs Trophic levels
Energy flow in ecosystems Energy flow • The energy usually starts with the sun. • Producers convert the energy by photosynthesis into food. • Energy is then transferred up the food chain: Primary, secondary, tertiary and quaternary consumers.
Trophic levels • Trophic levels shows the different feeding relationships in an ecosystem. • A food chain/web shows trophic levels indicates the flow of energy, and the arrows always point in the direction of energy flow. • Between the trophic levels, about 90% of the energy is lost to the environment
Pyramids of Production • The loss of energy with each transfer in a food chain is represented by a pyramid. • Trophic levels are stacked in blocks with primary producers forming the foundation of the pyramid. • The size of each block is proportional to the net production, of each trophic level.
Pyramid of Production
Feeding the World • • Which takes more land, eating plants or animals? • Which takes more fuel? • Which takes more water?
Name the organism!!!!!!!
Types of energy • Potential energy – The capacity to do work • Kinetic energy – What potential energy is converted to – Energy of motion • Chemical energy – Potential energy of molecules – Calories: protein - 4 C/g, Carbohydrates – 4 C/g, and fats – 9 C/g
Respiration and Photosynthesis
The four major macromolecules • • Carbohydrates Proteins Fats (Lipids) Nucleic Acids (DNA and RNA)